Drilling apparatus.



J. HENNESSY & E. A. GAPOGEFALO.

DRILLING APPARATUS.

APPLIOATION FILED 00112, 1009.

Patented Nov. 1, 1910.

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UNITED STATES PATENT ornion.

J OHN J. HEN NESSY AND EDWARD A. CAPOCEFALO, 0F SYRACUSE, NEW YORK.

DRILLING APPARATUS.

Specification of Letters Patent.

Patented Nov. 1, 1910.

T 0 all whom it may concern:

Be it known that we, J OIIN J. IIENNESSY and EDWARD A. OAroonrALo, ofSyracuse, in the county of Onondaga and State of New York, have inventeda certain new and useful Drilling Apparatus, of which the following is aspecification.

Our invention has for its object the production of a drilling apparatuswhich is particularly simple in construction and compact in itsorganization, and it consists in the combination and constructionshereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawing in which like characters designate the corresponding parts inall the views.

Figures 1 and 2 are longitudinal sectional views of our drillingapparatus, illustrating the movable parts thereof in difl'erentpositions.

This drilling apparatus comprises, generally, a case, a compressingpiston movable in one end portion of the case, a hammer piston movablein the central portion of the case, the pistons being spaced apart andunconnected, a drill spindle supported at the other end of the case andarranged in the path of the hammer piston, and a catch for holding thehammer piston in its starting or retracted position during thecompressing movement of the first mentioned piston, the case beingformed with open passages for permitting air to enter in front of thecompressing piston when said piston is at the end of its suction strokeand with open passages for permitting air to escape from in front of thehammer piston during the power stroke thereof and to enter the case infront of the hammer piston during the return stroke of the hammer pistoneffected by the suction stroke of the compressing piston.

As here illustrated the case is divided into two cylinders 1 and 2, indirect communication with each other, and the compressing piston 3 andhammer pistons 4 are, movable respectively in said cylinders.

As here illustrated the compressor and hammer cylinders 1 and 2 arearranged end to end in direct communication with each other andpreferably in axial alinement, the hammer cylinder 2 being of lessdiameter than the compressor cylinder. Although the cylinders are hereshown as formed of separate pieces which are bolted together, 1t isobvious that they may be formed integral.

The compressor cylinder 1 is formed with inlet passages 5 for the airlocated in its central portion, in front of the position occupied by thepiston 3 when said piston is at the end of its suction stroke. Thehammer cylinder 2 is formed with passages 6 at its outer end andpreferably with outlet passages 7 for the compressed airwhen the hammerpiston 4 is at the limit of its power stroke, the passages 7 beingpreferably located just behind the position occupied by thehammer-piston 4 when said piston is at the end of its power stroke. Thehammereylinder 2 also suitably holds a drill spindle 8, the head 9 ofsaid spindle being located within the cylinder 2 in the path of thehammer piston and a buffer spring 10 being located between the head 9and the outer end wall 11 of the hammer cylinder 2. Said hammer-cylinder2 is also provided at its upper end with spring-pressed catches 12 forentering a peripheral groove 13 formed in the hammer piston 4 andholding said piston 4 in its retracted or starting position, during thecompressing stroke of the piston 3 in the cylinder 1. These catches 12and their springs 14 are here shown as movable in guides formed inthreaded bosses 15 on which turn cap nuts 16 for tensioning the springs14 between the catches 12 and the nuts 16.

As here shown the hammer piston 4 is formed with a rearwardly extendingpush arm 17 for being engaged and forced by the compressing piston 3 outof engagement with said catches 12, as the piston 3 is nearing the endof its compression stroke. However this arm may be omitted and thesprings 14 of the catches so adjusted that they will be overcome whenthe piston 3 has compressed the air in the cylinder 1 to a predetermineddegree. Preferably the air space between the pistons 3 and 4 when thepistons are in the positions shown in Fig. 1, is greater than the airspace between the pistons when said pistons are in their position shownin Fig. 2, and the surplus air is discharged through the passages 7 whenthe hammer piston 4 is at the end of its power stroke. These spaces mayhowever be substantially of the same, so that no outlet passages 7 arenecessary. The passages 7 are preferably provided with check valves 18for preventing the rush of air in the cyl'- inder 2 behind the hammer 4,but such valves may be dispensed with if desired,

said passages 7 being then closed by the hammer piston upon its reboundfrom the head 9 of the spindle 8.

The compressing piston 8 may be actuated by any suitable means, hereshown as a drive shaft 19 supported by a bracket 20 on the cylinder 1and designed to be connected to a suitable motor, the shaft 19 having agear 21 thereon meshing with the gear 22 which is also supported by thebracket 20 and connected to the piston 1 by a link or pitman 23.

The operation of our drilling apparatus is as follows: Air enters thecompression cylinder through the passage 5 and is compressed during theout stroke of the piston 3 until the piston 3 engages the end of thepush arm 17 and moves the hammer piston 4 out of engagement with thecatches 12 (or in case the push arm is omitted, until the compression infront of the piston 3 overcomes the tension of the springs 12),whereupon the hammer piston 4 is impelled outwardly upon the head 9 ofthe drill spindle 8 pushing the air before it out through the vents ofpassages 6. WVhen the hammer is at the end of its power stroke, thesurplus air, if any, escapes through the passages 7. The compressorpiston then begins its suction stroke, drawing the piston 4 backwardlyuntil it is caught by the elements 12.

Our drill is particularly advantageous in that it has no mechanicallyactuated valves and is compact in its organization.

that we claim is 1. A pneumatic apparatus comprising a case, an aircompressing piston and a hammer piston movable in the case, the pistonsbeing spaced apart therein and being unconnected, the spaces in the casebehind the compressing piston and in front of the hammer piston beingunconnected, and a catch extending through the case for holding thehammer piston in its retracted or starting position during thecompression stroke of the first-mentioned piston, substantially as andfor the purpose described.

2. A. pneumatic apparatus comprising a case, an air compressing pistonmovable in. one end portion of the case, a hammer piston movable in theother end portion of the case, the pistons being spaced apart and beingunconnected, the case between the pistons being formed with an openpassage located to permit the inlet of air in front of the compressingpiston when at the end of its suction stroke, and with an open passagelocated to permit the air to escape from in front of the hammer pistonduring the power stroke thereof, the latter passage also permitting airto enter in front of the hammer piston during the return stroke thereof,in order that the hammer piston may be retracted by the suction of thecompressing piston, and a catch extending through the case for holdingthe hammer piston in its retracted position, substantially as and forthe purpose specified.

3. A pneumatic apparatus comprising a case, an air compressing pistonmovable in one end portion of the case, a hammer piston movable in theother end portion of the case, the pistons being spaced apart therein,and being unconnected, the spaces in the case behind the compressingpiston and in front of the hammer piston being unconnected, and the casebeing formed with an open passage located to permit the inlet of air infront of the compressing piston when said piston is at the end of itssuction stroke and with an open passage located to permit the escape ofair from in front of the ham mer piston during the power stroke thereof,the latter passage also permitting air to enter in front of the hammerpiston during the return stroke thereof, in order that the hammer pistonmay be retracted by the suction produced by the compressing piston, atool spindle supported at the hammer piston end of the case and havingone end located in the path of the hammer piston, and a catch forholding the hammer piston in its retracted or starting position duringthe compression stroke of the first-mentioned piston, substantially asand for the purpose set forth.

4. A pneumatic apparatus comprising a case, an air compressing pistonmovable in one end portion of the case, a hammer piston the pistonsbeing spaced apart and being unconnected, the spaces in the case behindthe compressing piston and in front of the hammer piston beingunconnected, and the case being formed with an open passage located infront of the position occupied by the head of the compressing pistonwhen at the end of its suction stroke, and with a passage openingdirectly into the outer air and lo cated near the position occupied bythe head of the hammer piston when at the end of its power stroke, and acatch extending through the case and engaging the hammer piston forholding the hammer piston in its retracted or starting position duringthe compression stroke of the first-mentioned piston, substantially asand for the purpose described.

5. A pneumatic apparatus comprising a ton reciprocally movable in thecase, one in advance of the other, the pistons being spaced aparttherein and being unconnected, a catch for holding the power piston inits retracted or starting position during the compression stroke of thecompressing piston, and means fixed to one piston and extending towardthe other piston in order to engage said other piston during thecompression stroke of the power piston from the catch, substantially asand for the purpose set forth.

movable in the other end portion of the case,

case, a compressing plston and a power pisfirst-mentioned piston andthereby force the e 6. A pneumatic apparatus comprising a case, acompressing piston and a powerpiston reciprocally movable in the caseone in advance of the other, the pistons being spaced a art therein andbeing unconnected, a catch for holding the power piston in its retractedor starting position during the compression stroke of the compressingpis ton, and a push arm fixed to one piston and extending toward theother piston in order to engage said other piston during the compresslonstroke of the compressing piston and thereby force the power piston fromthe catch, substantially as and for the pur pose set forth.

7. An air operated apparatus comprising a case, an air compressingpiston movable in one end portion of the case, a hammer piston movablein the other end portion of the case, the pistons being spaced apart andbeing unconnected, the spaces in the case vbehind the compressing pistonand in front of the power piston being unconnected, and V the case beingformed with an open inlet passage located in front of the positionoccupied by the head of the compressing piston when at the end of itssuction stroke, a passage opening directly into the outer air andlocated near the position occupied by-the head of its power piston whenat the end of its power stroke and with an outlet passage opening intothe space between the pistons and located just behind the positionoccupied by the hammer piston when the hammer piston is at the limit ofits powerstroke, acheck valve in said passage, and means fixed to onepiston and extending toward the other piston, in order to engage theother piston during the compression stroke of the first-mentioned pistonand thereby force the hammer piston from the catch and start it on itspower stroke, substantially as and for the purpose specified.

8. A drilling apparatus comprising an air compressor cylinder, a secondcylinder in direct communication with the compressor cylinder, a pistonmovable in the compressor cylinder, a hammer piston movable in thesecond cylinder, and having a peripheral depression and a spring-pressedcatch for entering said depression and holding the hammer piston at theinner end of the second cylinder during the compression stroke of thefirst-mentioned piston, substantially as and for the purpose described.

9. A pneumatic apparatus com rising a case, an air compressing piston,an a power piston movable in the case, the pistons being spaced aparttherein and being unconnected and the hammer piston being formed with aperipheral depression, the spaces in the case behind the compressingpiston and in front of the power iston belng unconnected, and a sring-pressed catch supported by the case an extending through the casein position to enter the peripheral depression of the hammer piston whenthe hammer piston is in its retracted or starting position,substantially as and for the purpose set forth.

10. A pneumatic apparatus comprising a case, an air compressing pistonand a hammer piston movable in the case, the pistons being spaced aparttherein and being unconnected, and the hammer piston being formed with aperipheral depression, the spaces in the case behind the compressingpiston and in front of the hammer piston being unconnected, aspring-pressed catch supported by the case in posltion to enter theperipheral depression of the power piston when the power piston is inits retracted or startin position, and means fixed to one piston ancprojecting toward the other piston in order to engage said other pistonduring the compression stroke of the firstmentioned piston and therebyforce the power piston from the catch and start the same on its powerstroke, substantially as and for the purpose described.

In testimony whereof, we have hereunto signed our names in the presenceof two attesting witnesses, at Syracuse, in the county of Onondaga, inthe State of New York, this 9th day of October, 1908.

JOHN J. HENNESSY. EDWARD A. CAPOGEFALO.

WVitnesses:

S. DAVIS, E. K. SEEMILLER.

